Nanoscale fracture mechanisms in defective α‐ quartz induced by compression: Insights from molecular dynamics simulation

Abstract Clarifying the fracture mechanisms at the nanoscale is essential for constructing a multiscale framework of rock fracture. In this study, molecular dynamics simulation is employed to investigate the fracture behavior and associated strength evolution in defective α ‐quartz containing either a single hole or double holes under uniaxial compression. The effects of hole size, strain rate, and temperature are analyzed in relation to crack initiation, propagation, and coalescence, and the resulting evolution of uniaxial strength. The results show that the uniaxial strength in all cases is negatively correlated with hole size, while the influence of strain rate is generally limited but varies with hole size. Elevated temperature can reduce both the Young's modulus and peak stress of defective α ‐quartz. Moreover, amorphized zones forming around the lateral edges of holes serve as the primary sites for fracture initiation in all cases, and wing‐like shear fractures represent the dominant propagation mode. The configuration with double holes promotes indirect coalescence in the rock bridge region, while strain rate influences the coalescence patterns depending on hole size. These findings could offer useful insights for developing multiscale models for rock fracture.